This is a basic pattern for an extensible JavaScript module. This example is based off: http://www.adequatelygood.com/JavaScript-Module-Pattern-In-Depth.html where you can find several more snippets.

module.js

var UTIL = (function (my, $) {

  // private variables
  var  privateVariable = 1;

  // private methods
  function privateMethod() {
    // ...
  }

  // public variables
  my.moduleProperty = 1;

  // public methods
  my.moduleMethod = function () {

    // You get access to jQuery
    $('document').bind( ... );

  };

  return my;

}(UTIL || {}, jQuery));